This resubmission of a 2-year developmental project proposes the first phase of a multi-phase project whose ultimate aim is reducing HIV/STD risk among youth already at risk for other psychosocial problems such as homelessness, substance abuse, and mental health problems. Central to the goals of this study is testing a model that integrates findings in the existing empirical literature with two theories: the IMB (Information- Motivation-Behavioral skills) model, an empirically validated theory of HIV risk reduction, and a recently proposed sexual health model that explicitly incorporates a holistic, positive view of sexual health. Our approach is based on the assumptions that: (1) an empirically tested theoretical model is critical to the field for use in intervention development, (2) such a model should account for the cultural, environmental, historical, intrapersonal, interpersonal, and behavioral experiences of a population, rather than a narrow focus on sexual behavior, given that these may need to be addressed for HIV intervention to be effective, and (3) an explicit recognition of individuals' strengths as well as challenges should be an inherent part of a theoretical model. In collaboration with a community advisory group, we propose to: (1) conduct elicitation research, (2) develop and pilot test survey instruments and procedures, (3) conduct a survey of 600 high school-age adolescents, (4) describe sample characteristics and the biases associated with different recruitment strategies, (5) empirically test the theoretical model, (6) determine key characteristics of and population preferences for interventions to prevent HIV/STD infection and enhance well-being; and identify existing interventions that might be modifiable for this purpose, and (6) use the results of these activities to outline web-based intervention protocols. As part of these activities, we will devise and evaluate measurement instruments, as well as recruitment, incentive, and data-gathering methodologies that can maximize access to this heterogeneous population. [unreadable] [unreadable] [unreadable]